Crucible.



PATENTED SEPT. 4, 1906.

B. A. COLBY.

GRUG IBLE. APPLICATION FILED NOV. 23, 1905.

WITNESSES:

w an and hence more easily crushedthan the solid 59' UNITED STATES PATENT OFFICE- EDWARD AEGOLBY, OF NEW'ARK, NEIV JERSEY.

GRUGIBLE.

Specification of Letters Patent Patented Sept. 4, 1906.

Application filed November 23, 1905,. Serial No. 288,635.

induced therein as a secondary circuit from aprimary circuit in suitable proximity.

The invention consists in the construction of the crucible in annular form having the chamber-surface of one wall frusto-conical, also in a crucible-lining of refractory material adapted to become crushed by the compressive strain of the material solidifying in said crucible.

The object of the invention is, first, to enlarge the crucibleopening, and so render itmore easily charged and the solidified material more eas' y extracted than if the walls were truly cylindrical, and, second, to rotect the crucible-Wall from ru'pture or cracEing due to the strains due to the solidifying mass therein. In the accompanying drawin s, Figure 1- is a transverse section of a crucib e embodying my invention. Fig.2 is a similar sectlon of a modified form thereof. 'Fig. 3 shows, on a smaller scale, an annular lining of friable material separate from' the crucible shown in Fig. I and ads ted'to-fitv therein. Fig. '4 shows a similar ining adapted to the crucible shown in Fig. Figs. 5 and 6 show lining-sections, of which the linings of Figs. 3 and 4 may, if desired, be composed.

$imilar letters of reference indicate like parts. j The crucible is made of any sultable refractory material molded into form in the usualwa AsshowninF' .1,the chambersurface of the outer wall der. The chamber-surface wall D is frusto-conical. if; t In order to protect th riicible frOnirupture, I apply to the surface 0 a E-of refractory material which islmore 'abl'e C of the inner refractory material ofthe crucible itself, or which even if of the same refracto material as said crucible is in any suits. 10 way made less dense or less resistant to the compressive strain due to solidifyingmetal in said crucible than an equal thickness of the is a right cylin-h refractory material of said crucible itself would be. Said lining may be originally in annular form, as shown in Figs. 3 and 4, and

simply inserted in place, or it may be com-' posedof sections, as shown in Figs. .5 and 6,

or it may be applied in a plastic state and left to harden before use. It is of course to be understood that the specific material or com ound of materials selected for the lining shal not be of a nature chemically to cornbine with the molten charge in the crucible to. roduce a detrimental effect therein.

n the modification shown in Fig. 2 the chamber-surface A of the outer wall B is inverted frusto-crinical, while the chamber-surface C of the inner wall D is a right cylinder.

The lining E, as before, is applied to the sur- 1 face 0 I claim 1. Arefractorycrucible-linin constructed to yield to the compressive straln of solidifying metal. A

2. A refractory lining for annular crucibles formed of friable material constructed to yield to the compressive strain of solidifying metal..

3. In combination with a crucible of refractory material, a refractory sistant to internal pressure t said crucible to which it is applied.

4. In combination with a crucible of relining less rean the wall ofstructed in sections to fit said crucib e and less resistant to internal pressure than the wall of said crucible to which it is su plied.

6.. A lining for annular crucibles ormed in sections of friable refractory material constructed to yield to the compressive strain of I solidifying metal.

7. In combination with an annular crucible of refractory] material, and on the chambersurface oft e inner wall thereof a refractory lining of material less resistant to internal pressure than the wall of said cylinder.

In testimony whereof I have affixed my signature in presence of two witnesses.

' Witnesses:

PARK BENJAMIN, Jr.,' WM. H. SIEGMAN.

EDWARD A. COLBY. 

